Keyboard for telegraph-transmitters.



C. E. NELSON.

KEYBOARD FOR TELEGRAPH TRANSMITTERS.

APPLICATION FILED SEPT. 3. 19M.

1,-157,714. Patented 00t.26,1915.

CARL ERIC NELSON, OF 'WILKINSBURG, PENNSYLVANIA.

KEYBOARD FOR TELEGRAPH-TRANSMITTERS.

I Specification of Letters Patent. v v

Patented Oct. 26, 1915.

Application filed September 3, 1914. Serial No. 859,955.

To all whom it may concern Be it known that I, CARL E. NnLsoN, a citizen of the United States, residing at Wilkinsburg, county of Allegheny, and State of Pennsylvania, have invented certain new and useful Improvements in Keyboards for Telegraph-Transmitters, of

which the following is a full, clear, and exact description.

The usual keyboard of the transmitter of a printing telegraph system is the practical counterpart of that used with mechanical typewriters. That is to say, it comprises a bank of keys, mounted on levers which, when depressed, perform the operations necessary for the transmission of the electrical impulses corresponding to the operated key, and to facilitate the manipulation of the keys, they are invariably arranged in tiers, each of which is slightly higher than the one in front of it.

In operating such keyboards the finger directed toward one key frequently touches the neXt adjacent key in the same line, with the result that two keys are depressed instead of one, and this is particularly objectionable in electrical transmitting keyboards where the function of a depressed key is merely to close a circuit or perform some other operation requiring the expenditure of very little power. Moreover, the simultaneous depression of two keys may result in the sending of any signal, and much time is required to correct a printed error in the receiving machine. This sort of accident seldom occurs in the case of two keys in differ ent horizontal rows, as they are at substantially different elevations, but it so frequently happens that two adjacent keys in the same row are unintentionally depressed at the same time that even highly skilled op= erators lose much valuable time in correcting mistakes which thus occur, and are insistent in their demands for anything that will prevent it. Nothing, to my knowledge, has heretofore been devised as a complete remedy for this trouble that did not involve very great complication in the mechanism of the keyboard, but by my present invention I secure fully and most satisfactorily the desired result by an extremely simple device. This consists of a'rocking frame, or what would be its mechanical equivalent, pivoted transversely under all of the key levers and containing notches or' cutaway portions alternately in its opposite sides. .The key 7 the uncut portions on the levers when depressed engage with the uncut portions of the frame and tilt the same, and the levers are so arranged that no two levers of keys adjacent to one another in the same row tilt the frame in the same direction.

To illustrate, assume a bank four rows; then the first key of each row to the left engages when depressed the uncut forward edge of the frame and tilts it forward. The second keys in each row engage the uncut portion of the rear edge of the frame and so on, so that of any two adjacent keys in the same rows, which tilt the frame 1n opposite directions, one key depressed locks the other up or if both keys are depressed with the same force and simultaneously, no effect will be produced. I

In practice it is found that there is nearly always what is known as a bias in favor of the correct key, so that although the wrong key may be touched, it is not pressed down with the same force, nor in advance of the right one. This simple device has been found to overcome in a most satisfactory manner all the objections which have heretofore been found to result from the tendency of any operator to touch more than one key at a time.

This device is illustrated in the accompanying drawings, in which Figure 1 is a schematic plan of a keyboard and Fig. 2 is a sectional view showing a key, and the aforesaid tilting frame.

A designates the keys and B the lever of any ordinary bank in the keyboard of a machine, such as a typewriter or electrical transmitter. It will be undertsood that all of the levers B lie in the same plane, although the rows of keys, as indicated in Fig. 2, are in dilferent planes. 1

Under the lever B is pivoted a two sided frame, or its equivalent, C in bearings D and which normally remains in the same position shown in Fig. 2. Along each edge or side of the frame a series of notches E are cut, the notches on one side lying opposite other, so that the results hereinbefore set forth will be produced when the levers are depressed.

What Iclaim, as my invention is:

1. In a keyboard of the kind described, the combination with the key levers of a tilting or rocking element supported and extending under all of said levers, and adapted to be rocked or tilted in opposite directions by the depression of any two adjacent of keys with keys in the same horizontal row, whereby the depression of one key causes said meniber to lock the adjacent keys against depresslon.

2-. In a keyboard of the kind described,

the combination with the key levers, of a rocking or tilting frame supported and extending under all of said levers, and having whereby the depression of one key locks the adjacent keys against depression.

keys in the same horizontal row,

3. In a keyboard of the kind described, 15

posite directions by the depression of any two adjacent keys in the same row. a

In testimony whereof I aflix my signature in the presence-of two subscribin witnesses.

, CARL ERIC N LSON. Witnesses:

R. L. KISTLER, J. E. WRIGHT.

'Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

5 Washington, D. 0." 

